1 # SPDX-License-Identifier: GPL-2.0
2 # Backward compatibility
3 asflags-y += $(EXTRA_AFLAGS)
4 ccflags-y += $(EXTRA_CFLAGS)
5 cppflags-y += $(EXTRA_CPPFLAGS)
6 ldflags-y += $(EXTRA_LDFLAGS)
8 # flags that take effect in current and sub directories
9 KBUILD_AFLAGS += $(subdir-asflags-y)
10 KBUILD_CFLAGS += $(subdir-ccflags-y)
12 # Figure out what we need to build from the various variables
13 # ===========================================================================
15 # When an object is listed to be built compiled-in and modular,
16 # only build the compiled-in version
17 obj-m := $(filter-out $(obj-y),$(obj-m))
19 # Libraries are always collected in one lib file.
20 # Filter out objects already built-in
21 lib-y := $(filter-out $(obj-y), $(sort $(lib-y) $(lib-m)))
24 # Unfortunately, we don't have information about ordering between -y
25 # and -m subdirs. Just put -y's first.
26 modorder := $(patsubst %/,%/modules.order, $(filter %/, $(obj-y)) $(obj-m:.o=.ko))
28 # Handle objects in subdirs
29 # ---------------------------------------------------------------------------
30 # o if we encounter foo/ in $(obj-y), replace it by foo/built-in.a
31 # and add the directory to the list of dirs to descend into: $(subdir-y)
32 # o if we encounter foo/ in $(obj-m), remove it from $(obj-m)
33 # and add the directory to the list of dirs to descend into: $(subdir-m)
34 __subdir-y := $(patsubst %/,%,$(filter %/, $(obj-y)))
35 subdir-y += $(__subdir-y)
36 __subdir-m := $(patsubst %/,%,$(filter %/, $(obj-m)))
37 subdir-m += $(__subdir-m)
38 obj-y := $(patsubst %/, %/built-in.a, $(obj-y))
39 obj-m := $(filter-out %/, $(obj-m))
41 # Subdirectories we need to descend into
42 subdir-ym := $(sort $(subdir-y) $(subdir-m))
44 # if $(foo-objs), $(foo-y), or $(foo-m) exists, foo.o is a composite object
45 multi-used-y := $(sort $(foreach m,$(obj-y), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y))), $(m))))
46 multi-used-m := $(sort $(foreach m,$(obj-m), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m))), $(m))))
47 multi-used := $(multi-used-y) $(multi-used-m)
48 single-used-m := $(sort $(filter-out $(multi-used-m),$(obj-m)))
50 # $(subdir-obj-y) is the list of objects in $(obj-y) which uses dir/ to
51 # tell kbuild to descend
52 subdir-obj-y := $(filter %/built-in.a, $(obj-y))
54 # Replace multi-part objects by their individual parts,
55 # including built-in.a from subdirectories
56 real-obj-y := $(foreach m, $(obj-y), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y))),$($(m:.o=-objs)) $($(m:.o=-y)),$(m)))
57 real-obj-m := $(foreach m, $(obj-m), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m))),$($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m)),$(m)))
60 # If CONFIG_OF_ALL_DTBS is enabled, all DT blobs are built
62 extra-$(CONFIG_OF_ALL_DTBS) += $(dtb-)
66 extra-y := $(addprefix $(obj)/,$(extra-y))
67 always := $(addprefix $(obj)/,$(always))
68 targets := $(addprefix $(obj)/,$(targets))
69 modorder := $(addprefix $(obj)/,$(modorder))
70 obj-m := $(addprefix $(obj)/,$(obj-m))
71 lib-y := $(addprefix $(obj)/,$(lib-y))
72 subdir-obj-y := $(addprefix $(obj)/,$(subdir-obj-y))
73 real-obj-y := $(addprefix $(obj)/,$(real-obj-y))
74 real-obj-m := $(addprefix $(obj)/,$(real-obj-m))
75 single-used-m := $(addprefix $(obj)/,$(single-used-m))
76 multi-used-m := $(addprefix $(obj)/,$(multi-used-m))
77 subdir-ym := $(addprefix $(obj)/,$(subdir-ym))
79 # Finds the multi-part object the current object will be linked into.
80 # If the object belongs to two or more multi-part objects, all of them are
81 # concatenated with a colon separator.
82 modname-multi = $(subst $(space),:,$(sort $(foreach m,$(multi-used),\
83 $(if $(filter $*.o, $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m))),$(m:.o=)))))
85 modname = $(if $(modname-multi),$(modname-multi),$(basetarget))
87 # These flags are needed for modversions and compiling, so we define them here
88 # $(modname_flags) defines KBUILD_MODNAME as the name of the module it will
89 # end up in (or would, if it gets compiled in)
90 name-fix = $(squote)$(quote)$(subst $(comma),_,$(subst -,_,$1))$(quote)$(squote)
91 basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget))
92 modname_flags = -DKBUILD_MODNAME=$(call name-fix,$(modname))
94 orig_c_flags = $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) \
95 $(ccflags-y) $(CFLAGS_$(basetarget).o)
96 _c_flags = $(filter-out $(CFLAGS_REMOVE_$(basetarget).o), $(orig_c_flags))
97 orig_a_flags = $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) \
98 $(asflags-y) $(AFLAGS_$(basetarget).o)
99 _a_flags = $(filter-out $(AFLAGS_REMOVE_$(basetarget).o), $(orig_a_flags))
100 _cpp_flags = $(KBUILD_CPPFLAGS) $(cppflags-y) $(CPPFLAGS_$(@F))
103 # Enable gcov profiling flags for a file, directory or for all files depending
104 # on variables GCOV_PROFILE_obj.o, GCOV_PROFILE and CONFIG_GCOV_PROFILE_ALL
107 ifeq ($(CONFIG_GCOV_KERNEL),y)
108 _c_flags += $(if $(patsubst n%,, \
109 $(GCOV_PROFILE_$(basetarget).o)$(GCOV_PROFILE)$(CONFIG_GCOV_PROFILE_ALL)), \
114 # Enable address sanitizer flags for kernel except some files or directories
115 # we don't want to check (depends on variables KASAN_SANITIZE_obj.o, KASAN_SANITIZE)
117 ifeq ($(CONFIG_KASAN),y)
118 _c_flags += $(if $(patsubst n%,, \
119 $(KASAN_SANITIZE_$(basetarget).o)$(KASAN_SANITIZE)y), \
120 $(CFLAGS_KASAN), $(CFLAGS_KASAN_NOSANITIZE))
123 ifeq ($(CONFIG_UBSAN),y)
124 _c_flags += $(if $(patsubst n%,, \
125 $(UBSAN_SANITIZE_$(basetarget).o)$(UBSAN_SANITIZE)$(CONFIG_UBSAN_SANITIZE_ALL)), \
129 ifeq ($(CONFIG_KCOV),y)
130 _c_flags += $(if $(patsubst n%,, \
131 $(KCOV_INSTRUMENT_$(basetarget).o)$(KCOV_INSTRUMENT)$(CONFIG_KCOV_INSTRUMENT_ALL)), \
135 # If building the kernel in a separate objtree expand all occurrences
136 # of -Idir to -I$(srctree)/dir except for absolute paths (starting with '/').
138 ifeq ($(KBUILD_SRC),)
139 __c_flags = $(_c_flags)
140 __a_flags = $(_a_flags)
141 __cpp_flags = $(_cpp_flags)
144 # -I$(obj) locates generated .h files
145 # $(call addtree,-I$(obj)) locates .h files in srctree, from generated .c files
146 # and locates generated .h files
147 # FIXME: Replace both with specific CFLAGS* statements in the makefiles
148 __c_flags = $(if $(obj),$(call addtree,-I$(src)) -I$(obj)) \
149 $(call flags,_c_flags)
150 __a_flags = $(call flags,_a_flags)
151 __cpp_flags = $(call flags,_cpp_flags)
154 c_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
155 -include $(srctree)/include/linux/compiler_types.h \
156 $(__c_flags) $(modkern_cflags) \
157 $(basename_flags) $(modname_flags)
159 a_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
160 $(__a_flags) $(modkern_aflags)
162 cpp_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
165 ld_flags = $(LDFLAGS) $(ldflags-y)
167 DTC_INCLUDE := $(srctree)/scripts/dtc/include-prefixes
169 dtc_cpp_flags = -Wp,-MD,$(depfile).pre.tmp -nostdinc \
170 $(addprefix -I,$(DTC_INCLUDE)) \
173 # Useful for describing the dependency of composite objects
175 # $(call multi_depend, multi_used_targets, suffix_to_remove, suffix_to_add)
177 $(foreach m, $(notdir $1), \
179 $(addprefix $(obj)/, $(foreach s, $3, $($(m:%$(strip $2)=%$(s)))))))
183 # ---------------------------------------------------------------------------
184 quiet_cmd_flex = LEX $@
185 cmd_flex = $(LEX) -o$@ -L $<
187 $(obj)/%.lex.c: $(src)/%.l FORCE
188 $(call if_changed,flex)
191 # ---------------------------------------------------------------------------
192 quiet_cmd_bison = YACC $@
193 cmd_bison = $(YACC) -o$@ -t -l $<
195 $(obj)/%.tab.c: $(src)/%.y FORCE
196 $(call if_changed,bison)
198 quiet_cmd_bison_h = YACC $@
199 cmd_bison_h = bison -o/dev/null --defines=$@ -t -l $<
201 $(obj)/%.tab.h: $(src)/%.y FORCE
202 $(call if_changed,bison_h)
205 # ===========================================================================
207 quiet_cmd_shipped = SHIPPED $@
208 cmd_shipped = cat $< > $@
210 $(obj)/%: $(src)/%_shipped
213 # Commands useful for building a boot image
214 # ===========================================================================
218 # target: source(s) FORCE
219 # $(if_changed,ld/objcopy/gzip)
221 # and add target to extra-y so that we know we have to
222 # read in the saved command line
225 # ---------------------------------------------------------------------------
228 cmd_ld = $(LD) $(LDFLAGS) $(ldflags-y) $(LDFLAGS_$(@F)) \
229 $(filter-out FORCE,$^) -o $@
232 # ---------------------------------------------------------------------------
234 quiet_cmd_objcopy = OBJCOPY $@
235 cmd_objcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@
238 # ---------------------------------------------------------------------------
240 quiet_cmd_gzip = GZIP $@
241 cmd_gzip = (cat $(filter-out FORCE,$^) | gzip -n -f -9 > $@) || \
245 # ---------------------------------------------------------------------------
246 DTC ?= $(objtree)/scripts/dtc/dtc
248 # Disable noisy checks by default
249 ifeq ($(findstring 1,$(KBUILD_ENABLE_EXTRA_GCC_CHECKS)),)
250 DTC_FLAGS += -Wno-unit_address_vs_reg \
251 -Wno-unit_address_format \
252 -Wno-avoid_unnecessary_addr_size \
257 ifneq ($(findstring 2,$(KBUILD_ENABLE_EXTRA_GCC_CHECKS)),)
258 DTC_FLAGS += -Wnode_name_chars_strict \
259 -Wproperty_name_chars_strict
262 DTC_FLAGS += $(DTC_FLAGS_$(basetarget))
264 # Generate an assembly file to wrap the output of the device tree compiler
265 quiet_cmd_dt_S_dtb= DTB $@
268 echo '\#include <asm-generic/vmlinux.lds.h>'; \
269 echo '.section .dtb.init.rodata,"a"'; \
270 echo '.balign STRUCT_ALIGNMENT'; \
271 echo '.global __dtb_$(subst -,_,$(*F))_begin'; \
272 echo '__dtb_$(subst -,_,$(*F))_begin:'; \
273 echo '.incbin "$<" '; \
274 echo '__dtb_$(subst -,_,$(*F))_end:'; \
275 echo '.global __dtb_$(subst -,_,$(*F))_end'; \
276 echo '.balign STRUCT_ALIGNMENT'; \
279 $(obj)/%.dtb.S: $(obj)/%.dtb FORCE
280 $(call if_changed,dt_S_dtb)
282 quiet_cmd_dtc = DTC $@
283 cmd_dtc = mkdir -p $(dir ${dtc-tmp}) ; \
284 $(CPP) $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
285 $(DTC) -O dtb -o $@ -b 0 \
286 $(addprefix -i,$(dir $<) $(DTC_INCLUDE)) $(DTC_FLAGS) \
287 -d $(depfile).dtc.tmp $(dtc-tmp) ; \
288 cat $(depfile).pre.tmp $(depfile).dtc.tmp > $(depfile)
290 $(obj)/%.dtb: $(src)/%.dts $(DTC) FORCE
291 $(call if_changed_dep,dtc)
293 dtc-tmp = $(subst $(comma),_,$(dot-target).dts.tmp)
296 # ---------------------------------------------------------------------------
298 # Bzip2 and LZMA do not include size in file... so we have to fake that;
299 # append the size as a 32-bit littleendian number as gzip does.
300 size_append = printf $(shell \
303 fsize=$$($(CONFIG_SHELL) $(srctree)/scripts/file-size.sh $$F); \
304 dec_size=$$(expr $$dec_size + $$fsize); \
306 printf "%08x\n" $$dec_size | \
307 sed 's/\(..\)/\1 /g' | { \
308 read ch0 ch1 ch2 ch3; \
309 for ch in $$ch3 $$ch2 $$ch1 $$ch0; do \
310 printf '%s%03o' '\\' $$((0x$$ch)); \
315 quiet_cmd_bzip2 = BZIP2 $@
316 cmd_bzip2 = (cat $(filter-out FORCE,$^) | \
317 bzip2 -9 && $(call size_append, $(filter-out FORCE,$^))) > $@ || \
321 # ---------------------------------------------------------------------------
323 quiet_cmd_lzma = LZMA $@
324 cmd_lzma = (cat $(filter-out FORCE,$^) | \
325 lzma -9 && $(call size_append, $(filter-out FORCE,$^))) > $@ || \
328 quiet_cmd_lzo = LZO $@
329 cmd_lzo = (cat $(filter-out FORCE,$^) | \
330 lzop -9 && $(call size_append, $(filter-out FORCE,$^))) > $@ || \
333 quiet_cmd_lz4 = LZ4 $@
334 cmd_lz4 = (cat $(filter-out FORCE,$^) | \
335 lz4c -l -c1 stdin stdout && $(call size_append, $(filter-out FORCE,$^))) > $@ || \
339 # ---------------------------------------------------------------------------
341 MKIMAGE := $(srctree)/scripts/mkuboot.sh
343 # SRCARCH just happens to match slightly more than ARCH (on sparc), so reduces
344 # the number of overrides in arch makefiles
345 UIMAGE_ARCH ?= $(SRCARCH)
346 UIMAGE_COMPRESSION ?= $(if $(2),$(2),none)
348 UIMAGE_TYPE ?= kernel
349 UIMAGE_LOADADDR ?= arch_must_set_this
350 UIMAGE_ENTRYADDR ?= $(UIMAGE_LOADADDR)
351 UIMAGE_NAME ?= 'Linux-$(KERNELRELEASE)'
355 quiet_cmd_uimage = UIMAGE $(UIMAGE_OUT)
356 cmd_uimage = $(CONFIG_SHELL) $(MKIMAGE) -A $(UIMAGE_ARCH) -O linux \
357 -C $(UIMAGE_COMPRESSION) $(UIMAGE_OPTS-y) \
359 -a $(UIMAGE_LOADADDR) -e $(UIMAGE_ENTRYADDR) \
360 -n $(UIMAGE_NAME) -d $(UIMAGE_IN) $(UIMAGE_OUT)
363 # ---------------------------------------------------------------------------
364 # Use xzkern to compress the kernel image and xzmisc to compress other things.
366 # xzkern uses a big LZMA2 dictionary since it doesn't increase memory usage
367 # of the kernel decompressor. A BCJ filter is used if it is available for
368 # the target architecture. xzkern also appends uncompressed size of the data
369 # using size_append. The .xz format has the size information available at
370 # the end of the file too, but it's in more complex format and it's good to
371 # avoid changing the part of the boot code that reads the uncompressed size.
372 # Note that the bytes added by size_append will make the xz tool think that
373 # the file is corrupt. This is expected.
375 # xzmisc doesn't use size_append, so it can be used to create normal .xz
376 # files. xzmisc uses smaller LZMA2 dictionary than xzkern, because a very
377 # big dictionary would increase the memory usage too much in the multi-call
378 # decompression mode. A BCJ filter isn't used either.
379 quiet_cmd_xzkern = XZKERN $@
380 cmd_xzkern = (cat $(filter-out FORCE,$^) | \
381 sh $(srctree)/scripts/xz_wrap.sh && \
382 $(call size_append, $(filter-out FORCE,$^))) > $@ || \
385 quiet_cmd_xzmisc = XZMISC $@
386 cmd_xzmisc = (cat $(filter-out FORCE,$^) | \
387 xz --check=crc32 --lzma2=dict=1MiB) > $@ || \
391 # ---------------------------------------------------------------------------
393 # Default sed regexp - multiline due to syntax constraints
395 # Use [:space:] because LLVM's integrated assembler inserts <tab> around
396 # the .ascii directive whereas GCC keeps the <space> as-is.
398 's:^[[:space:]]*\.ascii[[:space:]]*"\(.*\)".*:\1:; \
399 /^->/{s:->#\(.*\):/* \1 */:; \
400 s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \
404 # Use filechk to avoid rebuilds when a header changes, but the resulting file
406 define filechk_offsets
411 echo " * DO NOT MODIFY."; \
413 echo " * This file was generated by Kbuild"; \
416 sed -ne $(sed-offsets); \